I am currently writing some PHP form validation (I have already validated clientside) and have some repetitive code that I think would work well in a nice little PHP function. However I have having trouble getting it to work. I'm sure it's just a matter of syntax but I just can't nail it down. Any help appreciated. //Validate phone number field to ensure 8 digits, no spaces. if(0 === preg_match("/^[0-9]{8}$/",$_POST['Phone']) { $errors['Phone'] = "Incorrect format for 'Phone'"; } if(!$errors) { //Do some stuff here.... } I found that I was writing the validation code a lot and I could save some time and some lines of code by creating a function. //Validate Function function validate($regex,$index,$message) { if(0 === preg_match($regex,$_POST[$index],$message) { $errors[$index] = $message; } And call it like so.... validate("/^[0-9]{8}$/","Phone","Incorrect format for Phone"); Can anyone see why this wouldn't work? Note I have disabled the client side validation while I work on this to try to trigger the error, so the value I am sending for 'Phone' is invalid.